        * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
            font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
        }

        body {
            background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
            min-height: 100vh;
            padding: 20px;
            display: flex;
            flex-direction: column;
            align-items: center;
            justify-content: center;
        }

        .container {
            background: white;
            border-radius: 15px;
            box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
            padding: 30px;
            width: 100%;
            max-width: 400px;
            text-align: center;
        }

        h1 {
            color: #333;
            margin-bottom: 20px;
            font-size: 24px;
        }

        .upload-area {
            border: 2px dashed #3498db;
            border-radius: 10px;
            padding: 40px 20px;
            margin: 20px 0;
            cursor: pointer;
            transition: all 0.3s;
        }

        .upload-area:hover {
            background: #f8f9fa;
            border-color: #2980b9;
        }

        .upload-icon {
            font-size: 48px;
            color: #3498db;
            margin-bottom: 15px;
        }

        .file-input {
            display: none;
        }

        .upload-btn {
            background: #3498db;
            color: white;
            border: none;
            padding: 15px 30px;
            border-radius: 25px;
            font-size: 16px;
            cursor: pointer;
            transition: background 0.3s;
            margin-top: 20px;
        }

        .upload-btn:hover {
            background: #2980b9;
        }

        .upload-btn:disabled {
            background: #95a5a6;
            cursor: not-allowed;
        }

        .file-info {
            margin-top: 20px;
            padding: 15px;
            background: #ecf0f1;
            border-radius: 8px;
            display: none;
        }

        .status {
            margin-top: 20px;
            padding: 10px;
            border-radius: 5px;
            display: none;
        }

        .success {
            background: #d4edda;
            color: #155724;
            border: 1px solid #c3e6cb;
        }

        .error {
            background: #f8d7da;
            color: #721c24;
            border: 1px solid #f5c6cb;
        }

        .loading {
            display: none;
            margin-top: 20px;
        }

        .back-btn {
            margin-top: 20px;
            background: #95a5a6;
            color: white;
            border: none;
            padding: 10px 20px;
            border-radius: 5px;
            cursor: pointer;
            text-decoration: none;
            display: inline-block;
        }